#include "list.h"


/* Reads a sequence of numbers from input file to create a
 * list of numbers. After that takes input from the keyboard
 * for different operations.
 */

int main(int argc, char *argv[])
{
	List L;
	int number;
	char op;

	// create dummy cell
	L = (List) malloc(sizeof(Cell));
	L->element = 0; // no cell in the list yet
	L->next = NULL;

	if (argc > 2) { // wrong command
		printf("Command format: list [<filename>]\n");
		return 0;
	}

	if (argc == 2) { // input file is provided
		FILE *fp;
		int n, m;

		fp = fopen(argv[1], "r"); // open the file
		if (fp == NULL) { // file does not exist
			printf("Input file does not exist!\n");
			return 0;
		}

		fscanf(fp, "%d", &n); // number of numbers in file

		for (int i = 0; i < n; i++) { // read n numbers
			fscanf(fp, "%d", &m); // read a number
			insert_list(m, L);
		}

		fclose(fp);
	}

	// Now read input from keyboard
	printf("Please input operations\n");
	while (1) { // run indefinitely
		scanf(" %c", & op); // read the next operation
		if (op == 'e') // exit
			return 1;
		else if (op == 'p') // print the list
			print_list(L);
		else if (op == 's') { // search for a number
			scanf("%d", &number);
			if (search_list(number, L) != NULL) // number found
				printf("Number exists in the list\n");
			else
				printf("Number does not exist in the list\n");
		}
		else if (op == 'i') { // insert a number
			scanf("%d", &number);
			insert_list(number, L);
		}
		else { // delete a number
			scanf("%d", &number);
			if (delete_list(number, L) != -1) // number deleted
				printf("Number removed from the list\n");
			else
				printf("Number does not exist in the list\n");
		}
	}
}